Glassblowing For The Lab

There was a time when ordering some glassware from a distributor meant making a sizable minimum order, sending a check in the mail and waiting weeks for a box full of — hopefully intact — glassware to arrive. In those days, blowing your own glassware from glass tubes was fairly common and [Wheeler Scientific] has been doing a series on just how to do that. Even if you aren’t interested in building a chemistry lab, you might find the latest episode on making a gas discharge tube worth a watch. There are several videos and you can see a few of them below.

Of course, blowing glass is literally playing with fire, so be careful. Most important rule? Don’t inhale. Then again, for a lot of things, blowing glass doesn’t involve you actually blowing, but it is more like bending and shaping and — technically — what he shows is lampwork, not actual glassblowing, but that’s a technicality.

You need a torch, of course, and the one in the videos is a propane-fueled torch with an oxygen tank as well. Making a gas discharge tube also requires a little extra hardware including a cylinder of argon and a two-stage vacuum pump. You also need a way to excite the tube, but since you probably already have a tesla coil, that won’t be a problem.

There are other videos if you want to handcraft test tubes and a few other items. We are waiting to see what comes next. If your glassblowing interest is more artistic, check out [Jimmy the Torch]. Just be careful. Glassblowing can be a gateway drug to making your own tubes.

20 thoughts on “Glassblowing For The Lab

  1. Glassblowing seems like one of those things you get hyped up about doing until you actually try it and then you realize you are out of your depth. Honestly, I would be far more comfortable with something akin to injection molding glass… which apparently was recently invented.

    1. Glass blowing isn’t hard at all. Especially the lab stuff since it is made of, mostly, thinner stock.

      Glass blowing as in making vases, lamps and such may be a different story.

    2. it’s quite easy. Back in high school chemistry we made eyedroppers, pipettes, glass filaments, various tubes with bulbs. With only minutes of instruction you can make all kinds of lab glassware.

    3. As a scientific glassblower of 10 years, I must say it can become quite difficult. Yeah, blowing a bulb and making a bend is easy, but try making a Soxhlet extractor or a mercury diffusion pump. I’m just trying to assemble glass cubes from plates for a gas manifold right now and the process has taken me a lot of trial and error.
      Saying its easy is like me saying “Electrical engineering is easy, I learned how to solder and and light LED’s in Jr. High.”

      1. Yes tthere are plenty of things that require much more training, skill and special equipment, but the point was that there is quite a lot of very usefule glassware that can be made very easily and doesn’t require much more than a flame source and simple instructions. The commenter would be surprised how easy some of it is. None of the glassware that was actually included in my post is complicated to do at all and kind of fun to make.

  2. We did some lab glass work in junior year in high school. We made custom tube bends, fixed chips, and a condenser with a coil inside a larger tube over it. It was one of the best labs we had that year.

    1. Same. I had a science teacher in middle school who’d let us try almost anything in the classroom lab as long as we paid for the consumables and did our research first (school also had a decent-for-the-day science library). I spent a lot of lunch hours in that lab.

    1. They are precision ground taper fittings (avaialble in a range of sizes) and are almost interference fit.

      A smear of silicone grease and you have a gas-tight seal tolerant of reduced pressure (not vacuum) and slightly elevated pressure.

      There are clips available to keep components together, but you rarely need them. Laboratory stands and clamps are essential, or a modular framework for larger set-ups.

      There are whole catalogues of those components.

      The generic name (and trade name) of the system is Quickfit™

      Google “Quickfit” to get an idea of the size and breadth of the range.

    2. The etched segments are your standard taper ground joints, they’re made typically with an extra length of boro glass tubing from which the joint was tooled, like a sleeve of glass. With a sharp flame and proper technique, the ends of the sleeve and the apparatus are heated to fuse them .

    3. It’s not etched. It’s called ground glass and it’s machined (with a grinder) to be perfectly round and with a specific taper. It can be sealed with various greases made for the task or in some cases with a drop of sulfuric acid (yes really!)

  3. When I was in college in the late 70s, one of the older profs in the chem dept was the glass fabricator and had a shop set up. Watching him make through wall stuff like condensers was fascinating.

      1. https://www.cmog.org/set/featured-objects-fragile-legacy
        http://www.warmus.com/Blaschka%20Sea%20Creatures%20Cornell%20Warmus.htm

        U got a link to any of his artwork. These sealife recreations by the Blaschka family is easily the most incredible glass art ive ever seen. (Besides the 3.5 foot tall 10k$ bong with all of the classic Mario characters built in torch flame and a functional working nintendo on a chip with slots for nes and super nes housed in the base, all characters portrayed and colored perfectly, entirely hamdmade from borosilicate, words fail at conveying how incredible it is and sadly i dont know the artist name)

      2. This is ubiquitous: most chem departments had a paid glassblower until the 1990’s, with a glass lathe (a worthwhile topic of exploration all by itself) and full capability for making anything needed. I learned a bunch from our chem glassblower, but he too was definitely the last in line and they weren’t going to replace him when he retired.
        I think the transition to microchemistry in the late 1980s really changed lab glassware requirements: from big 24/40 setups down to these tiny milliliter setups.

  4. At Virginia Tech they had at least three full-time glassblowers and a large annealing oven. There was quite a demand for all-glass diffusion pumps with integral heater, as well as custom glassware. One of the guys had made an all-glass chess set, very nice.

    I learned a little glassblowing—joining tubes, making bends, even made a finger condenser. Even taught a class in it a few times. One thing I learned; it’s a skill that is highly dependent on practice. One of the VT glassblowers said that he could tell a difference in his ability after just a week’s spring break(!). Likewise I had to virtually re-learn how to do it each semester that I taught it. Learning how to rotate two pieces of glass tubing that are being joined takes a while; they have to be rotated evenly and at the same speed, no jerkiness.

    Slight burns—hot glass looks like cold glass—was just part of the ‘fun’. :)

  5. There was a time where I hated the new sodium vapor lights with the ugly orange color. Thankfully they are on the way out. I wanted to use some kind of blue glasses to cut down on the glare. I did a little research. Turns out that cobalt blue glass is used to cut the glare and eye damage from glass blowing because of the sodium in glass.

  6. My wife worked at a technical glassblowing place ages ago when we were in high school. Also, in college (chem major) there was an awesome glass shop and the glass blower was of Eastern European descent. He was retiring and they couldn’t find a replacement. Not sure what they did after that.
    I did some really limited glass work with soda lime (soft) glass but if you are going to do anything remotely useful with pyrex/borosilicate the major problem isn’t torches and stuff it is access to an annealing oven. Without that anything you make will probably break and shatter at a terrible time.

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